1. Field of the Invention
The present invention relates to a method for adjusting an exposure condition and an optical sensor module thereof, and more particularly to a method for adjusting an exposure condition of an optical sensor module and an optical sensor module applying the method.
2. Related Art
Currently, an image capture device has been widely used in the daily life. After the image capture device uses an optical sensor to capture an image and converts the image to digital signals, the digital signals are stored. Various kinds of applications can be designed by combining the digital signals captured by the image capture device with a digital image processing technology.
The image capture device is also applicable to a general pointing device, for example, a mouse. The pointing device emits light to a surface, and the light reflected from the surface is captured by the image capture device. After appropriate sampling, the pointing device obtains images at a plurality of time points. A digital processor in the pointing device compares the images at the adjacent time points, and judges a direction and distance of movement of the pointing device according to luminance differences of pixels in the images.
However, when the pointing device works on different surfaces, the different surfaces have varying strengths in reflecting light due to the surface materials. Thus, the intensity of the reflected light received by the pointing device also differs from each other. If the reflected light is captured under the same optical condition, a phenomenon of uneven brightness occurs so that the pointing device makes an error in judging the direction and distance of the movement.